While progress of terrestrial digital broadcasting and progress of fusion of communications and broadcast, digitalization in a broadcast field is progressing increasingly. Conventionally, program materials were recorded on package media, such as a video tape. Program materials are taken into a server via various digital interfaces, such as SDI (Serial Digital Interface) and transmitted to other servers, an editing device, etc. Since video data of the program materials once taken on the server is treated as a file, the video data is transmitted between the servers connected by the network, or is shared. For this reason, compatibility of data files needs to be strictly guaranteed between the devices which constitute a program production system.
Since standards of package media were decided strictly conventionally, as for the program materials recorded on the package media, mutual compatibility was guaranteed clearly physically. However, in the program material taken into devices as a file, a format is regarded as attachment of logical meaning and becomes independent of a physical format. Various formats exist not having compatibility with other formats from such a background.
In order to resolve complication caused by such mixture of formats, the MXF standard was established by SMPTE (Society of Motion Picture and Television Engineers) aiming at a unified file exchange format of broadcast industry. The MXF is like “a container” or “a wrapping paper” for packing coded various video data and voice data with metadata. By using this MXF, file exchange of the video data of the program materials through the network can be easily performed.
An art for performing file exchange using the MXF and playing the video data of the program included in the MXF is known (JP, P2006-139334A).
The file of MXF contains data other than the video data of the program material called metadata, such as an identification tag which identifies the data, an index data, etc. For this reason, when playing the video data of the program material, there is no video data during the time when the metadata is sent to a decoder. Therefore, in conventional technology, there is a problem that playback delay occurs by blank time of playback until following video data is sent.